>> it's all coming together. >> thanks for joining us. we'll be back at 6:00. see you then. bye. breaking news tonight, an nbc news exclusive, president trump detailing the last minute decision to stop an imminent strike on iran >> i said how many people are going to be killed >> the tense late night drama night drama playing out inside the white house, the president saying the military was locked and loaded, why he called off the mission with minutes to spare. and tonight his message to iran. >> i'm not looking for war and if there is, it'll be seen before. >> also tonight, a prominent writer and advice columnist assaulting her years ago in a famous department store dressing room what she says happened as the president flatly denies it and says he never even met her massive explosions rock the largest oil refinery on the east coast, the blast felt for miles,

the fire still burning tonight, and concerns about what's in the air and the potential effect on gas prices a desperate family pleading for answers, a young american student studying to be a doctor goes missing in mexico just after graduation fears he was kidnapped and he's the most celebrated first pick since lebron, zion williamson, with tears in his eyes, why he says it's all thanks to mom. good evening everyone. president trump holding his fire and his cards tonight. in an nbc news exclusive interview explaining to chuck todd why he called off a retaliatory attack on iran at virtually the last minute, describing his conversation with military commanders who were ready to pull the trigger in response to iran's downing of an american drone

but the president tonight still leaving a u.s. response on the table. let's start our coverage with kristen welker, and a dramatic day at the white house >> reporter: that's right. a mixture of relief and uncertainty at the white house as the president weighs his next move on iran, the commander in chief delivering a clear message. he doesn't want war, but he's still ready to strike. overnight high drama inside th white house, president trump on the brink of ordering air strikes against three different sites in iran responsible for shooting down the american drone. the president tweeting they are cocked and loaded before he called it off. >> nothing is green lighted until the end because things change >> you never gave a final warning? >> no, but we had something ready to go. >> planes in the air >> no, but they would have been pretty soon. and things would have happened to a point where you wouldn't turn back or couldn't turn back. so, they came and they said sir,

we're ready to go. we would like a decision i said i want to know something before you go, how many people will be killed in this case iranians. they said, came back said, sir, approximately 150. and i thought about it for a second i said, do you know what they shot down an unmanned drone, plane, whatever you want to call it and here we are sitting with 150 dead people that would have taken place probably within a half an hour after i said go ahead. and i didn't like it i didn't think it was -- i didn't think it was proportionate. >> reporter: the u.s. says iran shot down the drone over international aerospace which iran disputes. now the president sending this which is already under punishing sanctions. >> i'm not looking for war, and if there is, it'll be obliteration like you've never seen before. i'm not looking to do that you can't have a nuclear weapon. you want to talk good, otherwise

you'll have a bad economy. >> no preconditions. >> no preconditions. >> reporter: now democrats are demanding congressional approval but offering rar praise to the president. >> that would be very provocative and glad the president didn't take that >> reporter: tonight senior administration officials say all options are on the table this is richard engel, iran today showed off what it claimed to be the twisted pieces of the $110 million american drone it shot down allegedly collected near the coast and if not to be outdone by president trump's restraint, iran claimed it too held back saying an american aircraft with 35 crew members was also in its cross hairs. but they only targeted the unmanned drone still, iran's latest provocation shooting down that drone with a surface to air missile was incredibly dangerous with multiple civilian aircraft

in the same area as the drone. today, the faa banned american airliners from flying over parts of the persian gulf and gulf of oman and nearly a dozen international carriers including british airways, klm, and kwantis followed suit. just this week, iraqi officials say iran launched a rocket attack on an exxon mobile facility in iraq and tonight former military and intelligence officials say if president trump had carried out a strike, it would have added more fuel to the fire and reopened the pandora's box of middle east war. >> if he called up the strike because of legitimate concerns about collateral damage to civilians, he made the right call

>> and richard joins us now. richard there are new signs tonight there could be diplomatic efforts here. what do we know? >> well, lester, one thing about going all the way to the drink is that it either leads to a conflict or could force diplomacy. and the u.s. has requested a meeting on iran at the u.n. security counsel and it will be on the agenda in japan at the g20 summit with president trump attending. >> all right thank you. there's much more of chuck todd's interview with president trump sunday morning on "meet the press. there is new accusation tonight against president trump from a female columnist who says he sexual assaulted her more than two decades ago but tonight president trump says it never happened. anne thompson has the details. >> reporter: carroll has had many roles, advice columnist, writer, talk show host now in a new book excerpted today in new york magazine,

carol reveals a shocking claim saying president donald trump assaulted her in the 90s, an accusation is white house calls false and unrealistic. >> i had a run in with the president in a dressing room in bergdorfs. i fought it was shocking. it was against my will >> the department store is across fifth avenue from trump tower. she can't remember the exact date, either the fall of 1995 or spring of 1996, but she does remember trump recognizing her as that advice lady. she writes he asked her for help about trying on a body suit and into a dressing room >> the minute he closed the door, boom he threw me up against the wall and tried to kiss me it was so shocking to me >> she then says he forced himself on her it lasts three minutes, she

writes she pushes him off and runs out of the dressing room a friend of carol's confirmed to nbc news that carol told her about the alleged attack the next day >> it just became time for me to tell my story. and i hope it helps empower other women to come forward with their story because it is not easy >> in a statement tonight, president trump says i've never met this person in my life she is trying to sell a new book that should indicate her motivation it should be sold in the fiction section. the statement goes on to say, quote, it never happened he points out there is no >> lester, president trump is not the only powerful man that e. jean carol accuses of attacking her.

he says former anchor made unwanted advances years ago. he denies it now to the military courtroom in san diego a lot of people are reelin after the bombshell dropped in the middle of a war crimes trial of a navy seal tonight new testimony after another seal took the stand and said he was the one who actually killed the prisoner. steve patterson with more. >> reporter: today navy chief the defense optimistic admitting to a stunned courtroom that it was he, not gallagher, who killed an injured isis detainee gallagher's defense team said a sloppy investigation led to the

surprise confession. >> this is a shotty investigation. no investigator or prosecutor asked the question of what is the cause of death how much more embarrassment is the navy going to take before they say enough? >> scott is one of seven navy seals granted immunity in exchange for testimony if determined he lied on the stand, he can be charged with perjury. prosecutors will not drop premeditated murder charges against gallagher saying the credibility of a witness is for the jury to decide >> what they may do is convict him of some lesser offense, cruelty, assault but i think that panel will be extremely hard pressed to convince gallagher of murder >> reporter: tonight more seals testifying about his actions while deployed, a war crimes

trial now riddled with so many twists and turns, ultimately in the hands of seven service members deciding the fate of a decorated peer >> reporter: gallagher accused of several other offenses including using a sniper rifle to fire at unarmed civilians today a fellow sniper testified he was there when it happened. >> thank you in chicago, a new development in the jussie smollett case. a judge ordered the appointment of a special prosecutor to investigate accusations that the actor staged a racist hate crime against himself and why all the felony counts were suddenly dropped. the special prosecutor will have the power to reopen the case this week congress took up the issue of reparations to the descendants of slaves, but the legacy of slavery and how it shaped our justice system today is a subject lawyer and activist brian stevenson has been talkine the civil rights era and it's starting to sound like a three day carnival rosa parks didn't give up her seat on day one, martin luther king on day two, and day three

we changed the rules >> brian stevenson is used to making people feel uncomfortable about slavery. >> for the next century, we were dealing with the legacy. and that's why we lived through all of that violence and terror through lynchings. that's why we had lawed that codified segregation, and that's why our criminal justice system was so menacing to people of color. we are haunted in america by our history of racial inequality >> reporter: the new hbo documentary "true justice" details his life's journey and the creation of the equal justice initiative >> my clients have been broken by trauma, bias, and discrimination >> the documentary focuses on his fight against the death penalty, his appearances before the supreme court on behalf of death row inmates. >> prosecution ran out and told the media that the state of alabama got the worse killer that ever walked the streets in

birmingham off the streets that night. only it wasn't true. >> a lot of the document revolves around the story of anthony ray henton a death row inmate you represented why does his case move you >> he was wrongly accused. he was charged with two murders in the birmingham area he had dramatic evidence of his innocence. >> he was exonerated in 2015 after 30 years on alabama's death row. is ce, for me, is an indictment of everything that's problematic. it reflects the way in which we presume guilt when defendants of color are accused of something >> stevenson has quietly emerged as a powerful voice in the racial and criminal justice movement by confronting long-held historical narratives. he helped found the national memorial for peace and justice, documenting the history of lynchings in this country. i met him there last fall. >> you cannot understand the death penalty, particularly its

uniquely southern focus, without understanding lynching and the legacy all of these people were lynched because they were presumed dangerous and guilty >> with criminal justice reform now widely embraced, stevenson sees hope. you feel like you're moving the needle >> i think so. i always felt like we were screaming and it didn't seem like it was resonating i think that's changing. >> but stevenson insists real change will come when america owns its shame >> i think we have to own up to this history we have to talk honestly about the brutality of enslavement >> the hbo documentary on stevenson premiers next wednesday. now to our series "by big idea." tonight harry smith sits down with business man andrew yang. >> what's your big idea? >> my big idea is a freedom dividend of $1,000 a month for

every american adult starting at age 18 >> he is a business entrepreneur provocateur. >> hello new york city >> yang says his program is needed because one in three american jobs is at risk of being eliminated by new technology within the next 12 years. >> gdp is going to go up and up with things like self-driving trucks stock market prices correspond to the fortunes of the top 20% of americans and unemployment does not include people who have left the work force when you start digging into those numbers, you will see that we are falling apart >> yang's program, a thousand dollars a month for every american ages 18 and older would be opt in. people could choose to stick with other social programs he plans to pay for the benefit with a 10% value-added tax on goods and services >> so, how would it work literally? >> so, the way it works is i become president in 2021 everybody knows my idea is the freedom dividend

i don't need 80% of congress to pass this law. i just need 51%. >> check this out, 2,500 people in new york city's washington square in the rain to hear him speak. giving people money, a freedom dividend that's andrew yang's big idea. harry smith, nbc news, new york. >> check out other candidates sharing their big ideas at nbcnews.com/mybigidea. just graduated, feared kidnapped in mexico. his family appealing for hel

officials in mexico say a young american who was celebrating his graduation from med school is feared kidnapped here's miguel almaguer jessie had just graduated medical school

the 29-year-old arkansas native surrounded by family and friends on the very night he decided to celebrate in mexico. the newly minted doctor was kidnapped while his friend was beaten, shot, and killed >> nobody is helping us. >> reporter: with his family in arkansas pleading for the american government to help, police in mexico have no motive for the attack in the state, 319 have gone missing in the first four months of this year, up 80% over last year with police saying the attack is likely connected to organized crime, he is considered an innocent victim. the 29-year-old had dreams of helping others and supporting his mother >> he just wanted a night out with his friends, and now it's turned into this tragedy >> reporter: tonight a young american doctor kidnapped and now missing nearly a week in mexico

miguel almaguer, nbc news. up next for us the massive explosion that could impact gas price.

a massive explosion today at the biggest oil refinery on the east coast and it was felt for miles. ron allen in philadelphia tonight. >> reporter: without warning an enormous explosion jolted terrified residents awake. >> just a massive fire ball lit up the whole sky >> reporter: the fire at the refinery, the largest on the east coast gasoline and heating oil residents nearby ordered to shelter in place firefighters say a mixture of propane and butane ignited late today the fire contained but still burning.

>> it can't be put under control because of what's burning inside of it. >> reporter: it's the second fire at the refinery this month. >> what do we need >> clean air >> reporter: leaving some in the community concerned. >> we're tired of people with asthma, all kinds of lung problems >> reporter: tonight officials declared the air safe. with operations disrupted here at the refinery, some analysts predicting east coast gas prices could rise by 5 cents a gallon or more depending on the extent of the damage caused by the raging inferno >> ron allen, thank you. next a super star on the brink says it's all thanks to mom.

finally tonight the teenage sensation headed for greater heights. kevin tibbles on zion williamson's big night and his message to mom

>> the new orleans pelicans select zion williamson >> the 6'7" phennom is now a pelican. >> he's got star written all over him >> a teary eyed zion williamson saluting his role model. >> i wouldn't be here if not for my mom she did everything for me. i want to thank her. >> reporter: for mom, a hoop dream come true. >> to watch his hard work pay off and to watch this, we're so happy for him. >> reporter: folks in the big easy now have another reason to party. williamson already immortalized as he who blew out his shoe in a college game last season now set to sign an estimated $45 million contract a lucrative sneaker deal could pull in another 100 million. this super star shaping up okay

to be a slam dunk. >> that's nightly news i'm lester holt. thank you for watching everyone. good night and have a great weekend. they changed. >> right now at 6:00, a scathing report. vta responds to accusations it's one of the worst run transit agencies in the country. it could have been anyone. new details about two deadly stabbings on the peninsula. first, i.c.e. agents are getting ready for raids across the country, including here in the bay area. one of the targets, young people in this country illegally. the news at 6:00 starts right now. good evening. thanks for joining us. >> president trump warned this would happen. now we have confirmed a massive immigration raid will begin this weekend across the country. i.c.e. agents will pick up

undocumented immigrants and deport them. ten cities in all. among them, san francisco. this could be a traumatic weekend for a lot of people. christie smith is in the city with the latest. >> reporter: talk of a potential sunday raid on thousands of undocumented immigrants spread quickly in san francisco. >> this notion they're going to do this massive sweeping enforcement in targeted cities, it's offensive. >> reporter: this woman is with carecen, the central american resource center. she wants people to be informed but no afraid. >> it's important to note this promise he will deport thousands of people is a logistical challenge. i think even i.c.e. would admit that. >> reporter: the raids will target peo